view.html.php :
function displayXxxx() :
// Cancel
JToolBarHelper::cancel('categorie.cancel', "JTOOLBAR_CANCEL");
Second parameter is a language string.
You can create a new language string,
or change this string for all your component, in the language file.
In this case, this is a global native string, so the best is to create a new one.
By the way, the native Toolbar helper is available here :
administrator/includes/toolbar.php
There you can understand better wich parameter correspond to wich button.
